While not limited thereto, the present invention has particular utility in combination with apparatus for forming internal threads on the ends of tubing. After the end of the tube has been expanded, a threaded mandrel is inserted therein and a die is thereafter forced over the end of the tube. In this process, which is essentially a cold extrusion process, the die, as it is forced over the end of the tube, causes its inner periphery to conform to the threads on the mandrel. This is followed by rotation and removal of the mandrel from the tube end, leaving the cold-formed internal threads intact.
In this process, and as the die is forced over the mandrel, the resulting extrusion effect elongates the tube and forms a variable length flashing on its end. This flashing must be removed subsequently in a shearing process without deforming the tube end itself.
While the invention is useful in a threading operation as described above, it will be understood that it also has application to any manufacturing operation where it is necessary to shear off the end of a tube without deforming the same.